perf(git): implement batch file lookup via git diff-tree --stdin

src/interfaces/git-client.ts

@@ -30,7 +30,7 @@ export interface IGitClient {
   hasStagedChanges(): Promise<boolean>;
   getRepoRoot(): Promise<string>;
   isInsideRepo(): Promise<boolean>;
-  getFilesChanged(commitHash: string): Promise<readonly string[]>;
+  getFilesChanged(commitHashes: readonly string[]): Promise<ReadonlyMap<string, readonly string[]>>;
   countCommitsSince(path: string, sinceCommitHash: string): Promise<number>;
   resolveRef(ref: string): Promise<string>;
   getHeadMessage(): Promise<string>;

src/services/atom-repository.ts

@@ -207,20 +207,13 @@ export class AtomRepository {
       loreCommits.push({ raw, trailers });
     }
 
-    // Second pass: batch getFilesChanged calls with concurrency limit.
-    // Results accumulate in insertion order, maintaining 1:1 alignment with loreCommits.
-    const filesPerCommit: (readonly string[])[] = [];
-    for (let i = 0; i < loreCommits.length; i += GIT_FILES_CHANGED_BATCH_SIZE) {
-      const batch = loreCommits.slice(i, i + GIT_FILES_CHANGED_BATCH_SIZE);
-      const batchResults = await Promise.all(
-        batch.map(({ raw }) => this.gitClient.getFilesChanged(raw.hash)),
-      );
-      filesPerCommit.push(...batchResults);
-    }
+    // Second pass: bulk fetch file lists using high-performance batch mode.
+    const hashes = loreCommits.map(c => c.raw.hash);
+    const filesMap = await this.gitClient.getFilesChanged(hashes);
 
-    // Build atoms by pairing parsed trailers with their file lists
-    const atoms: LoreAtom[] = loreCommits.map(({ raw, trailers }, index) =>
-      this.buildAtom(raw, trailers, filesPerCommit[index]),
+    // Build atoms by pairing parsed trailers with their file lists from the batch result
+    const atoms: LoreAtom[] = loreCommits.map(({ raw, trailers }) =>
+      this.buildAtom(raw, trailers, filesMap.get(raw.hash) ?? []),
     );
 
     return atoms;

src/services/git-client.ts

@@ -122,15 +122,37 @@ export class GitClient implements IGitClient {
     }
   }
 
-  async getFilesChanged(commitHash: string): Promise<readonly string[]> {
+  async getFilesChanged(commitHashes: readonly string[]): Promise<ReadonlyMap<string, readonly string[]>> {
+    if (commitHashes.length === 0) return new Map();
+
     const stdout = await this.exec([
       'diff-tree',
-      '--no-commit-id',
+      '--stdin',
       '--name-only',
       '-r',
-      commitHash,
-    ]);
-    return stdout.trim().split('\n').filter(line => line.length > 0);
+    ], commitHashes.join('\n'));
+
+    const result = new Map<string, string[]>();
+    const requestedHashes = new Set(commitHashes);
+    let currentHash: string | null = null;
+
+    const lines = stdout.split('\n');
+    for (const line of lines) {
+      const trimmed = line.trim();
+      if (!trimmed) continue;
+
+      // Git outputs the full hash on its own line when using --stdin.
+      // We whitelist the hash to ensure we don't misidentify a file path
+      // that happens to be 40 or 64 characters long.
+      if (requestedHashes.has(trimmed)) {
+        currentHash = trimmed;
+        result.set(currentHash, []);
+      } else if (currentHash) {
+        result.get(currentHash)!.push(trimmed);
+      }
+    }
+
+    return result;
   }
 
   async countCommitsSince(path: string, sinceCommitHash: string): Promise<number> {
@@ -292,21 +314,26 @@ export class GitClient implements IGitClient {
    * Execute a git command and return stdout.
    * Throws GitError on non-zero exit or other errors.
    */
-  private async exec(args: readonly string[]): Promise<string> {
-    try {
-      const { stdout } = await execFile('git', args as string[], {
+  private async exec(args: readonly string[], input?: string): Promise<string> {
+    return new Promise((resolve, reject) => {
+      const child = execFileCb('git', args as string[], {
         cwd: this.cwd,
         maxBuffer: 10 * 1024 * 1024, // 10MB buffer for large repos
         encoding: 'utf-8',
+      }, (error, stdout, stderr) => {
+        if (error) {
+          const execError = error as { stderr?: string; code?: number };
+          const actualStderr = stderr || execError.stderr || error.message;
+          reject(new GitError(`git ${args[0]} failed: ${actualStderr}`));
+        } else {
+          resolve(stdout);
+        }
       });
-      return stdout;
-    } catch (error: unknown) {
-      if (error instanceof Error) {
-        const execError = error as { stderr?: string; code?: number };
-        const stderr = execError.stderr ?? error.message;
-        throw new GitError(`git ${args[0]} failed: ${stderr}`);
+
+      if (input !== undefined && child.stdin) {
+        child.stdin.write(input);
+        child.stdin.end();
       }
-      throw new GitError(`git ${args[0]} failed: unknown error`);
-    }
+    });
   }
 }

tests/unit/commands/commit-amend.test.ts

@@ -15,7 +15,7 @@ function createMockGitClient(): IGitClient {
     hasStagedChanges: vi.fn().mockResolvedValue(true),
     getRepoRoot: vi.fn().mockResolvedValue('/repo'),
     isInsideRepo: vi.fn().mockResolvedValue(true),
-    getFilesChanged: vi.fn().mockResolvedValue([]),
+    getFilesChanged: vi.fn().mockResolvedValue(new Map()),
     countCommitsSince: vi.fn().mockResolvedValue(0),
     resolveRef: vi.fn().mockResolvedValue('abc1234'),
     getHeadMessage: vi.fn().mockResolvedValue(''),

tests/unit/services/atom-repository.test.ts

@@ -2,7 +2,7 @@ import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { AtomRepository } from '../../../src/services/atom-repository.js';
 import type { IGitClient, RawCommit } from '../../../src/interfaces/git-client.js';
 import type { PathQueryOptions } from '../../../src/types/query.js';
-import type { LoreTrailers } from '../../../src/types/domain.js';
+import type { LoreTrailers, LoreId } from '../../../src/types/domain.js';
 import { CustomTrailerCollection } from '../../../src/types/custom-trailer-collection.js';
 
 /**
@@ -86,9 +86,16 @@ function createMockGitClient(overrides: Partial<IGitClient> = {}): IGitClient {
     hasStagedChanges: vi.fn(async () => false),
     getRepoRoot: vi.fn(async () => '/repo'),
     isInsideRepo: vi.fn(async () => true),
-    getFilesChanged: vi.fn(async () => []),
+    getFilesChanged: vi.fn(async (hashes: string[]) => {
+      const map = new Map<string, string[]>();
+      for (const hash of hashes) {
+        map.set(hash, []);
+      }
+      return map;
+    }),
     countCommitsSince: vi.fn(async () => 0),
     resolveRef: vi.fn(async () => 'abc123'),
+    getHeadMessage: vi.fn(async () => 'message'),
     ...overrides,
   };
 }
@@ -146,7 +153,7 @@ describe('AtomRepository', () => {
     it('should return atoms for a file target', async () => {
       const commit = makeLoreCommit({ loreId: 'a1b2c3d4' });
       vi.mocked(gitClient.log).mockResolvedValue([commit]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(['src/auth.ts']);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([['abc12345', ['src/auth.ts']]]));
 
       const gitLogArgs = makeGitLogArgs();
       const options = makeQueryOptions();
@@ -171,7 +178,7 @@ describe('AtomRepository', () => {
       };
 
       vi.mocked(gitClient.log).mockResolvedValue([loreCommit, nonLoreCommit]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(['src/auth.ts']);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([['abc12345', ['src/auth.ts']]]));
 
       const result = await repo.findByTarget(makeGitLogArgs(), makeQueryOptions());
 
@@ -221,7 +228,7 @@ describe('AtomRepository', () => {
       const commit1 = makeLoreCommit({ hash: 'aaa', author: 'alice@example.com', loreId: 'aaaa1111' });
       const commit2 = makeLoreCommit({ hash: 'bbb', author: 'bob@example.com', loreId: 'bbbb2222' });
       vi.mocked(gitClient.log).mockResolvedValue([commit1, commit2]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(['src/auth.ts']);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([['aaa', ['src/auth.ts']], ['bbb', ['src/auth.ts']]]));
 
       const options = makeQueryOptions({ author: 'alice' });
       const result = await repo.findByTarget(makeGitLogArgs(), options);
@@ -237,7 +244,7 @@ describe('AtomRepository', () => {
         makeLoreCommit({ hash: 'ccc', loreId: 'cccc3333' }),
       ];
       vi.mocked(gitClient.log).mockResolvedValue(commits);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(['src/auth.ts']);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map(commits.map(c => [c.hash, ['src/auth.ts']])));
 
       const options = makeQueryOptions({ limit: 2 });
       const result = await repo.findByTarget(makeGitLogArgs(), options);
@@ -250,7 +257,7 @@ describe('AtomRepository', () => {
     it('should find an atom by its Lore-id', async () => {
       const commit = makeLoreCommit({ loreId: 'deadbeef' });
       vi.mocked(gitClient.log).mockResolvedValue([commit]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(['src/auth.ts']);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([[commit.hash, ['src/auth.ts']]]));
 
       const result = await repo.findByLoreId('deadbeef');
 
@@ -261,7 +268,7 @@ describe('AtomRepository', () => {
     it('should return null if no atom matches the Lore-id', async () => {
       const commit = makeLoreCommit({ loreId: 'a1b2c3d4' });
       vi.mocked(gitClient.log).mockResolvedValue([commit]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue([]);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map());
 
       const result = await repo.findByLoreId('deadbeef');
 
@@ -289,7 +296,7 @@ describe('AtomRepository', () => {
         makeLoreCommit({ hash: 'bbb', loreId: 'bbbb2222' }),
       ];
       vi.mocked(gitClient.log).mockResolvedValue(commits);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue([]);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([['aaa', []], ['bbb', []]]));
 
       const result = await repo.findAll();
 
@@ -307,7 +314,7 @@ describe('AtomRepository', () => {
         trailers: trailersRaw,
       };
       vi.mocked(gitClient.log).mockResolvedValue([commit]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue([]);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([['aaa', []]]));
 
       const result = await repo.findAll();
 
@@ -364,7 +371,7 @@ describe('AtomRepository', () => {
       const authCommit = makeLoreCommit({ subject: 'feat(auth): add login', loreId: 'aaaa1111' });
       const dbCommit = makeLoreCommit({ subject: 'fix(database): fix query', loreId: 'bbbb2222' });
       vi.mocked(gitClient.log).mockResolvedValue([authCommit, dbCommit]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue([]);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([[authCommit.hash, []], [dbCommit.hash, []]]));
 
       const result = await repo.findByScope('auth', makeQueryOptions());
 
@@ -375,7 +382,7 @@ describe('AtomRepository', () => {
     it('should match scope case-insensitively', async () => {
       const commit = makeLoreCommit({ subject: 'feat(Auth): add login', loreId: 'aaaa1111' });
       vi.mocked(gitClient.log).mockResolvedValue([commit]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue([]);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([[commit.hash, []]]));
 
       const result = await repo.findByScope('auth', makeQueryOptions());
 
@@ -385,7 +392,7 @@ describe('AtomRepository', () => {
     it('should return empty array when no scope matches', async () => {
       const commit = makeLoreCommit({ subject: 'feat(auth): add login', loreId: 'aaaa1111' });
       vi.mocked(gitClient.log).mockResolvedValue([commit]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue([]);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([[commit.hash, []]]));
 
       const result = await repo.findByScope('payments', makeQueryOptions());
 
@@ -395,7 +402,7 @@ describe('AtomRepository', () => {
     it('should handle commits without scope in subject', async () => {
       const commit = makeLoreCommit({ subject: 'fix: typo', loreId: 'aaaa1111' });
       vi.mocked(gitClient.log).mockResolvedValue([commit]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue([]);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([[commit.hash, []]]));
 
       const result = await repo.findByScope('auth', makeQueryOptions());
 
@@ -413,7 +420,7 @@ describe('AtomRepository', () => {
 
       // First call for initial atoms, second call for findByLoreId
       vi.mocked(gitClient.log).mockResolvedValue([commit1, commit2]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue([]);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([['aaa', []], ['bbb', []]]));
 
       // Parse the initial atoms ourselves
       const initialAtoms = [{
@@ -518,7 +525,7 @@ describe('AtomRepository', () => {
       const commitB = makeLoreCommit({ hash: 'bbb', loreId: 'bbbb2222', trailerExtras: 'Related: aaaa1111' });
 
       vi.mocked(gitClient.log).mockResolvedValue([commitA, commitB]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue([]);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([['aaa', []], ['bbb', []]]));
 
       const atomA = {
         loreId: 'aaaa1111',
@@ -558,7 +565,7 @@ describe('AtomRepository', () => {
 
       // findByLoreId will search all commits
       vi.mocked(gitClient.log).mockResolvedValue([commitB, commitC, commitD]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue([]);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([['bbb', []], ['ccc', []], ['ddd', []]]));
 
       const atomA = {
         loreId: 'aaaa1111',
@@ -635,35 +642,36 @@ describe('AtomRepository', () => {
         trailers: '',
       };
       vi.mocked(gitClient.log).mockResolvedValue([loreCommit, nonLoreCommit]);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(['src/auth.ts']);
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(new Map([['abc12345', ['src/auth.ts']]]));
 
       await repo.findByTarget(makeGitLogArgs(), makeQueryOptions());
 
-      expect(gitClient.getFilesChanged).toHaveBeenCalledTimes(1);
-      expect(gitClient.getFilesChanged).toHaveBeenCalledWith('abc12345');
+      expect(gitClient.getFilesChanged).toHaveBeenCalledWith(['abc12345']);
     });
 
-    it('should handle more commits than batch size', async () => {
+    it('should handle many commits in a single batch', async () => {
       const commits = Array.from({ length: 25 }, (_, i) =>
         makeLoreCommit({ hash: `hash${i}`, loreId: `${String(i).padStart(8, '0')}` }),
       );
       vi.mocked(gitClient.log).mockResolvedValue(commits);
-      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(['file.ts']);
+
+      const filesMap = new Map<string, string[]>();
+      commits.forEach(c => filesMap.set(c.hash, ['file.ts']));
+      vi.mocked(gitClient.getFilesChanged).mockResolvedValue(filesMap);
 
       const result = await repo.findByTarget(makeGitLogArgs(), makeQueryOptions());
 
       expect(result).toHaveLength(25);
-      expect(gitClient.getFilesChanged).toHaveBeenCalledTimes(25);
+      expect(gitClient.getFilesChanged).toHaveBeenCalledTimes(1);
+      expect(vi.mocked(gitClient.getFilesChanged).mock.calls[0][0]).toHaveLength(25);
     });
 
     it('should propagate getFilesChanged errors', async () => {
       const commit = makeLoreCommit({ loreId: 'deadbeef' });
       vi.mocked(gitClient.log).mockResolvedValue([commit]);
       vi.mocked(gitClient.getFilesChanged).mockRejectedValue(new Error('git failed'));
 
-      await expect(
-        repo.findByTarget(makeGitLogArgs(), makeQueryOptions()),
-      ).rejects.toThrow('git failed');
+      await expect(repo.findByTarget(makeGitLogArgs(), makeQueryOptions())).rejects.toThrow('git failed');
     });
   });
 });

tests/unit/services/git-client.test.ts

@@ -0,0 +1,61 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { GitClient } from '../../../src/services/git-client.js';
+import { execFile as execFileCb } from 'node:child_process';
+
+vi.mock('node:util', async () => {
+  const actual = await vi.importActual('node:util');
+  return {
+    ...actual,
+    promisify: (fn: any) => fn, // Simplified mock
+  };
+});
+
+vi.mock('node:child_process', () => ({
+  execFile: vi.fn(),
+}));
+
+describe('GitClient', () => {
+  const client = new GitClient('/test/cwd');
+
+  beforeEach(() => {
+    vi.resetAllMocks();
+  });
+
+  describe('getFilesChanged', () => {
+    it('should correctly parse git diff-tree output', async () => {
+      const hashes = ['aaaa111122223333444455556666777788889999', 'bbbb111122223333444455556666777788889999'];
+      const mockOutput = `${hashes[0]}\nfile1.ts\nfile2.ts\n${hashes[1]}\nfile3.ts\n`;
+
+      vi.mocked(execFileCb).mockImplementation(((cmd: string, args: any, opts: any, callback: any) => {
+        callback(null, mockOutput, '');
+      }) as any);
+
+      const result = await client.getFilesChanged(hashes);
+
+      expect(result.get(hashes[0])).toEqual(['file1.ts', 'file2.ts']);
+      expect(result.get(hashes[1])).toEqual(['file3.ts']);
+    });
+
+    it('should be robust against file paths that look like hashes', async () => {
+      const hashes = ['aaaa111122223333444455556666777788889999'];
+      // A file path that is exactly 40 chars and hexadecimal
+      const sneakyPath = '1234567890123456789012345678901234567890'; 
+      const mockOutput = `${hashes[0]}\n${sneakyPath}\nfile.ts\n`;
+
+      vi.mocked(execFileCb).mockImplementation(((cmd: string, args: any, opts: any, callback: any) => {
+        callback(null, mockOutput, '');
+      }) as any);
+
+      const result = await client.getFilesChanged(hashes);
+
+      // The sneaky path should be treated as a file, not a new commit
+      expect(result.get(hashes[0])).toEqual([sneakyPath, 'file.ts']);
+    });
+
+    it('should return an empty map for empty input', async () => {
+      const result = await client.getFilesChanged([]);
+      expect(result.size).toBe(0);
+      expect(execFileCb).not.toHaveBeenCalled();
+    });
+  });
+});